html,body {
    padding: 0;
    margin: 0;
}
.main {
    display: flex;
    flex-direction: column;
}
.header {
    display: flex;
    flex: 1;
    height: 1rem;
    background-color: antiquewhite;
}
.slideshow {
    display: flex;
    flex: 1;
    height: 3rem;
    background-color: burlywood;
}
.nav {
    display: flex;
    flex: 1;
    justify-content: center;
    padding: .5rem;
}
.nav li {
    display: flex;
    flex: 1;
    height: 1rem;
    margin-right: .5rem;
    list-style: none;
}
.nav li:last-child {
    margin-right: 0;
}
.nav li:nth-of-type(n) {
    background-color: blueviolet;
}
.nav li:nth-of-type(2n) {
    background-color: aqua;
}
.content {
    display: flex;
    flex: 1;
}
.content .left, .right {
    display: flex;
    height: 6rem;
}
.content .left {
    flex: 2;
    background-color: antiquewhite;
}
.content .right {
    flex: 1;
    background-color: burlywood;
}
.footer {
    display: flex;
    flex: 1;
    height: 2rem;
    background-color: darkorange;
}